scholarly journals Active Graphene Plasmonics with a Drift-Current Bias

ACS Photonics ◽  
2021 ◽  
Author(s):  
Tiago A. Morgado ◽  
Mário G. Silveirinha
Keyword(s):  
Drift Current ◽  
Graphene Plasmonics

scholarly journals DRIFT CURRENTS OF CLEAN AND SLICK SEA SURFACES

1982 ◽  
Vol 1 (18) ◽  
pp. 143
Author(s):  
Jin Wu
Keyword(s):  
Surface Film ◽  
Offshore Structures ◽  
Sea Surface ◽  
Clean Surface ◽  
Dynamic Interactions ◽  
Drift Current ◽  
Stress Coefficient ◽  
Wind Velocities ◽  
Wave Induced ◽  
Surface Drift

Drift currents near sea surface govern movement and dispersion of man-made discharges near the sea surface, and influence design, deployment, and stability of offshore structures. The wind-induced drift currents and the wave-induced mass transports at the sea surface are separately estimated. The total surface drift current, the sum of wind- and wave-induced components, agree well with oceanic data (Hughes, 1956). The mass transport of waves over slick surface is greater than that over clean surface due to dynamic interactions between the surface film and waves. On the other hand, the wind-stress coefficient of slick surface is smaller than that of clean surface, resulting in a smaller wind-induced drift current over the slick surface. Available laboratory results (Alofs and Reisbig, 1972) on slick movements are reanalyzed to provide basis for estimating movements of slicks of various sizes over waves of different lengths under different wind velocities.

scholarly journals Towards fully atomistic modeling of graphene plasmonics

2021 ◽  
Author(s):  
Tommaso Giovannini ◽  
Luca Bonatti ◽  
Chiara Cappelli
Keyword(s):  
Atomistic Modeling ◽  
Graphene Plasmonics

Laboratory studies of wind–wave interactions

1968 ◽  
Vol 34 (1) ◽  
pp. 91-111 ◽  
Author(s):  
Jin Wu
Keyword(s):  
Surface Roughness ◽  
Wind Stress ◽  
Water Surface ◽  
Wind Wave ◽  
Wave Drag ◽  
Average Height ◽  
Drift Current ◽  
Stress Coefficient ◽  
Wide Range ◽  
Wind Velocities

The present study consists of wind profile surveys, drift current measurements and water surface observations for a wide range of wind velocities in a wind–wave tank. It is confirmed that the velocity distribution essentially follows the logarithmic law near the water surface and the velocity-defect law toward the outer edge of the boundary layer. The wind stresses and surface roughnesses calculated from these distributions are divided into two groups separated by the occurrence of the wave-breaking phenomenon. For low wind velocities the surface roughness is dictated by ripples, and the wind-stress coefficient varies with U0−½, where U0 is the free-stream wind velocity. The surface roughness is proportional to the average height of the basic gravity wave at higher wind velocities; the stress coefficient is then proportional to U0. In addition, it is found that Charnock's expression (k ∝ u*2/g) holds only at high wind velocities, and that the constant of proportionality determined from the present experiment correlates very well with field observations. A new technique, involving the use of various-sized surface floats to determine the drift current gradient and the surface drift current, has been developed. A good agreement is shown between the gradients obtained from the measured currents and those determined from the wind stresses. Finally, the wind-stress coefficient is shown to be larger than the friction coefficient for turbulent flow along a solid rough surface; the difference is shown to be the wave drag of the wind over the water surface.

Radiation pattern reconfigurable graphene plasmonics-based nanoantenna

2021 ◽  
Vol 15 (04) ◽  
Author(s):  
Arun Kumar Varshney ◽  
Nagendra P. Pathak ◽  
Debabrata Sircar
Keyword(s):  
Radiation Pattern ◽  
Graphene Plasmonics

Explosive interaction of gravity-capillary triads as the initial stage of “bag-breakup” droplet generation mechanism at high winds 

2021 ◽  
Author(s):  
Dmitry Kozlov ◽  
Yuliya Troitskaya
Keyword(s):  
Water Surface ◽  
Hydrodynamic Instability ◽  
Spatial Scales ◽  
Generation Mechanism ◽  
Droplet Generation ◽  
Theoretical Physics ◽  
Small Scale ◽  
Wind Drift ◽  
Hurricane Wind ◽  
Drift Current

<p>The present work is a theoretical study of the hydrodynamic instability of the water-air interface, the development of which may result in the “bag breakup” fragmentation. This phenomenon begins with the appearance of a small-scale elevation of the water surface, which increases and turns into a small liquid “sail” or “bag”, limited by a thicker rim, and finally bursts into splashes. According to the results of laboratory experiments [1]–[3], the “bag breakup” fragmentation is the most effective droplet generation mechanism at hurricane wind speeds.</p><p>We propose a hypothesis that the formation of the initial elevations of the water surface, which undergoes fragmentation, is caused by the hydrodynamic instability of disturbances of the wind drift current in the water. A weakly nonlinear stage of instability in the form of a resonant three-wave interaction has been studied. It has been discovered that the nonlinear resonant interaction of a triad of wind drift perturbations, of which one wave is directed along the flow, and the other two are directed at an angle to the flow, leads to an explosive increase of amplitudes as it was in [4]. Within the framework of the piecewise-continuous model of the drift current profile, the characteristic time and spatial scales of disturbances have been found and it has been shown that their characteristic dependences on the air friction velocity are consistent with the previously obtained experimental data.</p><p>Acknowledgements</p><p>This work was supported by RFBR projects (19-35-90053, 19-05-00249) and the Foundation for the Advancement of Theoretical Physics and Mathematics “BASIS”.</p><p> </p>

scholarly journals Influence of Tidal Current, Wind, and Wave in Hebei Spirit Oil Spill Modeling

2020 ◽  
Vol 8 (2) ◽  
pp. 69 ◽  
Author(s):  
Kwang-Ho Lee ◽  
Tag-Gyeom Kim ◽  
Yong-Hwan Cho
Keyword(s):  
Oil Spill ◽  
Tidal Current ◽  
Stokes Drift ◽  
Wind Drift ◽  
Drift Current ◽  
External Forces ◽  
Efdc Model ◽  
Spilled Oil ◽  
Environmental Fluid ◽  
Good Agreement

The purpose of this study is to investigate the effects of three external forces (tidal current, wind, and waves) on the movement of oil spilled during the Hebei Spirit oil spill accident. The diffusion of the spilled oil was simulated by using a random walk (RW) model that tracks the movement caused by advection-diffusion assuming oil as particles. For oil simulation, the wind drift current generated by wind and tidal current fields were computed by using the environmental fluid dynamics code (EFDC) model. Next, the wave fields were simulated by using the simulating waves nearshore (SWAN) model, and the Stokes drift current fields were calculated by applying the equation proposed by Stokes. The computed tidal currents, wind drift currents, and Stokes drift currents were applied as input data to the RW model. Then, oil diffusion distribution for each external force component was investigated and compared with that obtained from satellite images. When the wind drift currents and Stokes drift currents caused by waves were considered, the diffusion distribution of the spilled oil showed good agreement with that obtained from the observation.

scholarly journals Graphene Plasmonics: Fully Atomistic Approach for Realistic Structures

2020 ◽  
Vol 11 (18) ◽  
pp. 7595-7602
Author(s):  
Tommaso Giovannini ◽  
Luca Bonatti ◽  
Marco Polini ◽  
Chiara Cappelli
Keyword(s):  
Graphene Plasmonics
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